X-Git-Url: https://git.proxmox.com/?p=pve-docs.git;a=blobdiff_plain;f=vzdump.adoc;h=a2eec20f528af3b5d192081cd75d2c40b96e67d4;hp=2939cbed8936d83303dedfb0b0eb4e16f8e35658;hb=c7678c11fd51ef56a7dad30a355024c2cf2acfca;hpb=77973c0ba21adfcf6bc8e51cd0251d63c02b7b09

diff --git a/vzdump.adoc b/vzdump.adoc
index 2939cbe..a2eec20 100644
--- a/vzdump.adoc
+++ b/vzdump.adoc
@@ -25,42 +25,68 @@ Backup and Restore
 include::attributes.txt[]
 endif::manvolnum[]
 
-'vzdump' is a utility to make consistent backups of running guest
-systems. It basically creates an archive of the guest private area,
-which also includes the guest configuration files. 'vzdump' currently
-supports LXC containers and QemuServer VMs. There are several ways to
-provide consistency (option `mode`), depending on the guest type.
+Backups are a requirements for any sensible IT deployment, and {pve}
+provides a fully integrated solution, using the capabilities of each storage
+and each guest system type. This allows the system administrator to fine tune via
+the `mode` option between consistency of the backups and downtime of the guest 
+system. Proxmox VE backups are always full backups - containing the VM/CT
+configuration and all data.
+Backups can be started via the GUI or via the `vzdump` command line tool.
+
+.Backup Storage
+
+Before a backup can run, a backup storage must be defined.
+Refer to the Storage documentation on how to add a storage. A backup storage
+must be a file level storage, as backups are stored as regular files.
+In most situations, using a NFS server is a good way to store backups.
+You can save those backups later to a tape drive, for off-site archive.
+
+.Scheduled Backup
+
+Backup jobs can be scheduled so that they are executed automatically on
+ specific days and times, for selectable nodes and guest systems.
+Configuration of scheduled backups is done at the Datacenter level in the GUI,
+which will generate a cron entry in /etc/cron.d/vzdump.
+
+Backup modes
+------------
+There are several ways to provide consistency (option `mode`), 
+depending on the guest type.
 
-.Backup `mode` for VMs:
+.Backup modes for VMs:
 
 `stop` mode::
-
-This first performns a clean shutdown of the VM to make sure it is
-stopped. It then starts the VM in suspended mode and uses the qemu
-backup feature to dump all data. If the VM was running, we start
-(resume) it immediately after starting the qemu backup task. This
-keeps the downtime as low as possible.
+This mode provides the highest consistency of the backup, at the
+cost of a downtime in the VM operation.
+It works by executing an orderly shutdown of the VM, and then runs a background
+Qemu process to backup the VM data. After the backup is complete, the 
+Qemu process resumes the VM to full operation mode if it was previously running.
 
 `suspend` mode::
 
-This mode does not really make sense for qemu. Please use snapshot
-mode instead.
+This mode is provided for compatibility reason, and suspends the VM before
+calling the `snapshot` mode. Since suspending the VM results in a longer 
+downtime and does not necessarily improve the data consistency, 
+the use of the `snapshot` mode is recommended instead.
 
 `snapshot` mode::
 
-This mode simply starts a qemu live backup task. If the guest agent
-is enabled (`agent: 1`) and running, it calls 'guest-fsfreeze-freeze'
-and 'guest-fsfreeze-thaw' to improve consistency.
+This mode provides the lowest operation downtime, at the cost of a small
+inconstancy risk.
+It works by performing a Proxmox VE live backup, in which data blocks are copy
+while the VM is running. If the guest agent is enabled (`agent: 1`) and running,
+it calls 'guest-fsfreeze-freeze' and 'guest-fsfreeze-thaw' to improve
+consistency.
 
 A technical overview of the Proxmox VE live backup for QemuServer can
 be found online
 https://git.proxmox.com/?p=pve-qemu-kvm.git;a=blob;f=backup.txt[here].
 
-NOTE: Qemu backup provides snapshots on any storage type. It does
-not require that the underlying storage supports snapshots.
-
+NOTE: For VMs, this _snapshot_ mode relates to the fact that the backup is
+performed while the VM is running. This has here nothing to do with file systems
+snapshots and can be operated on any kind of storage.
 
-.Backup `mode` for Containers:
+.Backup modes for Containers:
 
 `stop` mode::